Squeeze in a little ride time after work.

Take a quick ride on your mountain bike with all the essentials packed in Osprey's Viper Hydration Pack. This small, streamlined backpack has enough room for your helmet, pump, tube repair kit, and the included Hydraulics LT 2.5L reservoir. The LidLock system secures your helmet when you're not on your bike. Osprey made this pack with well-ventilated Airscape and BioStretch mesh, and the back panel has an Atlion foam framesheet to enhance stability without interfering your mobility on the mountain.

Airscape back panel

BioStretch shoulder straps

Removable webbing waist belt

Hydraulics LT 2.5L reservoir included

LidLock helmet attachment system

Front stash pocket

Zippered shoulder strap pocket

Upper side compression straps

Tech SpecsSize

Tech Specs

Material

[main] 210D polyester, [accent, bottom] 420D nylon packcloth

Volume

3L (183cu in)

Support/Suspension

Airscape back panel, Atilon foam

Shoulder Straps

BioStretch

Waist Belt

yes, removable

Hydration Compatible

yes

Reservoir Included

yes, 2.5L Hydraulics LT

Access

front panel

Pockets

1 zippered stash, 1 shove-it, 1 shoulder strap

Helmet Carry

yes, LidLock

Compression

yes, side straps

Dimensions

17 x 8 x 6in

Recommended Use

mountain biking

Manufacturer Warranty

lifetime

Size

Osprey

Packs

Xenith

M

L

XL

Torso

18 - 21in(46 - 53cm)

20 - 23in(51 - 58cm)

22 - 25in(56 - 63cm)

Hip

30 - 34in(76 - 86cm)

33 - 37in(84 - 94cm)

> 36in(> 91cm)

Aether 70, 85

S

M

L

XL

Torso

16 - 19in(40 - 48cm)

18 - 21in(46 - 53cm)

20 - 23in(51 - 58cm)

22 - 25in(56 - 63cm)

Hip

<31in(79cm)

30 - 34in(76 - 86cm)

33 - 37in(84 - 94cm)

> 36in(> 91cm)

Aether 60, Atmos

S

M

L

Torso

16 - 19in(40 - 48cm)

18 - 21in(46 - 53cm)

20 - 23in(51 - 58cm)

Hip

<31in(79cm)

30 - 34in(76 - 86cm)

33 - 37in(84 - 94cm)

Waypoint (Men's)

M

L

Torso

18 - 21in(46 - 53cm)

20 - 23in(51 - 58cm)

Hip

30 - 34in(76 - 86cm)

33 - 37in(84 - 94cm)

Kestrel, Talon

S/M

M/L

Torso

16 - 20in(40 - 51cm)

19 - 23in(48 - 58cm)

Hip

26 - 45in(65 - 114cm)

28 - 50in(70 - 127cm)

Stratos, Manta 28/36, Zealot, Syncro

S/M

M/L

Torso

16 - 19in(40 - 48cm)

18 - 21in(46 - 53cm)

Hip

26 - 45in(65 - 114cm)

28 - 50in(70 - 127cm)

Ariel 65

XS

S

M

L

Torso

14 - 17in(36 - 43cm)

16 - 19in(40 - 48cm)

18 - 21in(46 - 53cm)

20 - 23in(51 - 58cm)

Hip

24 - 45in(60 - 114cm)

24 - 45in(60 - 114cm)

27 - 48in(69- 121cm)

29 - 55in(72 - 140cm)

Xena, Ariel 55/75

XS

S

M

Torso

14 - 17in(36 - 43cm)

16 - 19in(40 - 48cm)

18 - 21in(46 - 53cm)

Hip

24 - 45in(60 - 114cm)

24 - 45in(60 - 114cm)

27 - 48in(69- 121cm)

Aura, Aura AG

XS

S

M

L

Torso

14 - 17in(35.5 - 43cm)

16 - 19in(40 - 48cm)

18 - 21in(46 - 53cm)

20 - 23in(51 - 58cm)

Hip

24 - 45in(60 - 114cm)

24 - 45in(60 - 114cm)

27 - 48in(69- 121cm)

29 - 55in(72 - 140cm)

Waypoint (Women's)

S

M

Torso

16 - 19in(40 - 48cm)

18 - 21in(46 - 53cm)

Hip

24 - 45in(60 - 114cm)

27 - 48in(69- 121cm)

Tempest, Kyte

XS/S

S/M

Torso

13 - 17in(33 - 43cm)

16 - 20in(40 - 51cm)

Hip

24 - 45in(60 - 114cm)

26 - 45in(65 - 114cm)

Sirrus, Mira 26/34

XS/S

S/M

Torso

15 - 18in(38 - 46cm)

17 - 20in(43 - 51cm)

Hip

24 - 45in(60 - 114cm)

26 - 45in(65 - 114cm)

Exos, Variant, Mutant

S

M

L

Torso

16 - 19in(40 - 48cm)

18 - 21in(46 - 53cm)

20 - 23in(51 - 58cm)

Hip

24 - 45in(60 - 114cm)

27 - 48in(69- 121cm)

29 - 55in(72 - 140cm)

Kode, Farpoint

S/M

M/L

Torso

15 - 19in(38 - 48cm)

18 - 22in(46 - 56cm)

Hip

26 - 45in(65 - 114cm)

28 - 50in(70 - 127cm)

Volt

One Size

Torso

17 - 22in(43 - 56cm)

Hip

25 - 50in(64 - 127cm)

Manta 20

One Size

Torso

18 - 21in(46 - 53cm)

Hip

25 - 50in(64 - 127cm)

Raptor, Viper

One Size

Torso

15 - 21in(38 - 53cm)

Hip

25 - 50in(64 - 127cm)

Viva

One Size

Torso

14 - 19in(36 - 48cm)

Hip

25 - 50in(64 - 127cm)

Mira 18

One Size

Torso

15 - 18in(38 - 46cm)

Hip

25 - 50in(64 - 127cm)

Raven, Verve, Reverb

One Size

Torso

14 - 18in(36 - 46cm)

Hip

25 - 50in(64 - 127cm)

Rev

Match to usual apparel size

Poco Child Carrier

One Size

Torso

15.5 - 21.5in(39.5 - 54.5cm)

Hip

25 - 50in(64 - 127cm)

Ace (12 - 16 years)

One Size

Torso

14 - 20in(35 - 50cm)

Hip

25 - 50in(64 - 127cm)

Jib (10 - 14 years)

One Size

Torso

13 - 19in(33 - 48cm)

Hip

25 - 50in(64 - 127cm)

How to Measure:

For best results, have someone take the measurement for you.

Torso:

Start at the iliac crest (the top of your hipbone that you can feel like a shelf on the side of your body). From this level on your spine, measure to the C7 vertebrae, the knobby bone at the base of your neck when you put your head down. Make sure to keep your back straight while having the measurement taken.

Comment on George Pointon's review:

Difficult To Use, Poor Design

Familiarity: I've used it several times

If I had known how the reservoir functioned in this pack I would not have ordered it. My camelbak allows filling with the reservoir in the pack, by simply twisting the lid off. This requires you to remove the entire pack, then slide off a clip, then squeeze to force it to open. It's a ridiculously convoluted system that adds nothing in the way of benefits, it just makes it more difficult and time consuming to refill. Will never buy an Osprey pack ever again.